Immobilized pH Gradients: Theory and Methodology [antikvár]

Introduction It is my pleasure to sandwich the present manual between two 'electrodes': 'Galvani' and (in the Post Scriptum) 'Volta'. They are the two Italians who most contributed to the development and understanding of electric phenomena, the first from a physiological point of view, the second from a physical approach. This is not, by all means, to diminish the contributions from all other scientists, but, being an Italian too, I feit particularly obliged to pay a tribute to them. Luigi Galvani (Bologna, 1737-1798) (Fig. 0.1) became a professor of Anatomy and Surgery at the University of Bologna in 1763. In 1780, he started his famous experiments on electricity in frogs. He noticed that, when skinned frogs, hanging out from his balcony, with a metal wire connected to the central spinal nerve, were wired to the metal railings of the balcony, contractions were produced during lightning in a thunderstorm. He thought he had discovered 'animal electricity' and his studies led him to formulate a theory on the electric nature of nerve fluid, theory which initiated modern electrophysiology. The conclusive experiment was produced on September 20, 1786, when Galvani observed that, when a bridge was made between the spinal nerve and an extremity of a skinned frog leg, an electric reaction was produced in frog muscle (see Fig. 0.2). However, the bridge consisted of two segments of two different metais, zinc and copper. At that time, a physicist from the University of Pavia, Alessandro Volta, was on leave to follow a course with Galvani (clerici vagantes, i.e., itinerant students, were quite populär in universities since the Middle Ages; thus the Erasmus Program, now promoted by the European Community to move students around european universities, is a rediscovery of an old principle) and was quite thrilled by this experiment. He feit intuitively that contact between two metais would create electricity; that if insulated zinc were touched against insulated copper, the